Health professionals and consumers may change their choices when the same risks and risk reductions are presented using alternative statistical formats.
Based on the results of 35 studies reporting 83 comparisons, we found the risk of a health outcome is better understood when it is presented as a natural frequency rather than a probability .
On average, people perceive risk reductions to be larger and are more persuaded to adopt a health intervention when its effect is presented in relative terms (eg using relative risk reduction which represents a proportional reduction) rather than in absolute terms (eg using absolute risk reduction which represents a simple difference).
We found no differences between health professionals and consumers. The implications for clinical and public health practice are limited by the lack of research on how these alternative presentations affect actual behaviourbehaviour. However, there are strong logical arguments for not reporting relative values alone, as they do not allow a fair comparison of benefits and harms as absolute values do.
in: http://onlinelibrary.wiley.com/o/cochra ... frame.html